Hacker News new | ask | show | jobs
by userbinator 4009 days ago
but hydrogen still presents a lot of handling and transport complexities for use as something like a motor vehicle fuel

With this efficiency, it could be feasible to just split the water at the point-of-use.

I'm reminded of the "run your car on water/save fuel" scams which involved "HHO generators" - basically the same thing - located in the intake manifold and connected to a source of water and electricity from the car's electrical system. This time, it might actually do something interesting...

4 comments

With this efficiency, it could be feasible to just split the water at the point-of-use.

If you have the power source at the point of use, it's still more efficient to just use that for propulsion.

There has to be a way to store the hydrogen for later use.

I'm reminded of the "run your car on water/save fuel" scams which involved "HHO generators"

I used to work with a guy who was convinced that his HHO generator would yield all kinds of increased fuel efficiency on his gas guzzling pickup truck.

He didn't have the background to understand why it's not possible to get more energy out of burning the brown's gas than he used to create it.

While increased efficiency in the splitting of water molecules is a great thing, there's still basic thermodynamics.

> With this efficiency, it could be feasible to just split the water at the point-of-use.

Isn't it still a pretty slow process? Efficiency doesn't matter if it generates a trickle of H, and you need a large fixed volume.

Splitting at point of use is silly anyway- why use power to split water into hydrogen you can use for a fuel cell to generate power, at the point of use?

The engine could draw on a smallish stored reservoir of H2 for normal operation. That reservoir could then be continuously supplied with H2 from the process until it hits some pressure metric after which the system temporarily turns off until the pressure in the reservoir dips below some threshold.
okay, so if we need a fixed volume X, and we have a reservoir of (1/2) X, then we only have to wait on the slow trickle of the remaining 1/2 instead of the full amount.

Plus, what do you think the H2 is for? Generally, we think about using it in a fuel cell. Which generates electricity. And the idea of using electricity to split out H2 in order to generate electricity, all in one place....

You're adding complexity, but I'm not sure you're actually improving on simpler approaches.

That doesn't make much sense. How are you going to make H2 inside a car? You need lots of electricity. Why not just have an electric motor?
> With this efficiency, it could be feasible to just split the water at the point-of-use.

You need electricity at the point of use, which is mobile for a motor vehicle. If you have mobile electricity, using it to get hydrogen out of water, so you can run your hydrogen powered generator to get electricity doesn't make a lot of sense.

> With this efficiency, it could be feasible to just split the water at the point-of-use.

Hu? Why? You have electricity, you use it to make hydrogen, then burn the hydrogen and power something?

Why not just use the electricity directly?